Typewriting machine



Aprll 7, 1931. w. F. HELMOND 1,799,900

TYPEWRITING MACHINE Filed May 10, 1928 t g V 3 l4 FIGJ. l2

Patented V Apr. 7, 1931 UNI-TED STATES PATENT OFFICE WILLIAM F. HELMOND, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO UNDER- WOOD ELLIOTT FISHER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELA- WARE Application filed May 10, 1928.

This invention relates to segmental abut-- ments or anvils for the type-bars of typewriting machines, and one object is to reduce the noise made by a type-bar contacting with 5 the same, and improve the action of the typebar, and reduce the wear.

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a side elevation of an Underwood typewriting machine, showing my anvil applied thereto.

Figure 2 is a perspective view of a segment with the novel anvil inserted therein, one of the cover-plates being broken away to show the invention more clearly.

Figure 3 is a perspective view of the fiber anvil and its retaining spring removed from the segment.

Key-levers 10, through means of hellcranks 11, are adapted to swing type-bars 12 upwardly and rearwardly against the front face of a platen 13 mounted in a carriage 14. The type-bars 12 are pivoted at 15 in slots 16 25 of a type-bar segment 17 the axis through the pivots forming an arc.

In this form of the invention the type-bar segment 17 is channeled or milled out as at 18. Said channel is undercut at 19, leaving 0 overhanging shoulders 20 resulting in the cross-sectional shape shown in Fi'gure2. In channel 18 slidingly fits a vulcanized fiber anvil 21 normally projecting beyond the face of the segment, and having longitudinal 35 flanges 22 for engaging the overhanging shoulders 20. Said fiber anvil is so made as to permit of an air-cushion space 23. In space 23 is placed under tension a spring 24 which is narrower than channel 18 to permit of expansion. Said spring in cross-section has a bow or channel 25 and flanges 26. Said flanges 26 abut the rear surface of the anvil 21, while at the same time the bow or channel 25 abuts the rear wall of the channel 18.

Due to the tension in spring 24 it normally TYPE'WRITING MACHINE Serial No. 276,600.

holds itself and the anvil 21 in engagement with the channel 18 and prevents movement of the unit along the channel. This relation of anvil, spring and type-bar segment is shown in Figure 2.

At each end of channel 18 can be a springbracket 27 carrying a roller 28 for the purpose disclosed in my Patent No. 1,571,946 of February 9, 1926, and having a base 29. Said bases 29 are so attached by screws 30 to the type-bar segment as to span and close each end of the channel 18. For the same purpose the bases alone could be used when they would constitute plates 29. Against said bases or plates the ends of fiber and of spring normally abut. When it is desirable on account of wear to present an unworn surface to the type-bars, one end of fiber can be filed ofi slightly and the anvil be pulled along the channel.

It will be seen that there is provided a slightly yielding anvil, which at the same time has great durability. This is accomplished by the use of companion parts forming a unit which is combined with the typebar segment. Said two parts are of different material that the advantages and disadvantages of each material may be respectively utilized or avoided, The material that directly receives the impact of the type-bars is vulcanized fiber of arcuate shape and having slightly elastic properties. This slight elasticity cushions the blows and therefore assures less noise than does cast iron. The fiber also assures less wear on the contacting type-bars. Furthermore, said fiber possesses suflicient rigidity to insure a whip-like snap to the type-bar, which carries the type to a contact with the platen, after the type-bar has been arrested by the anvil. This quicker and advantageous rebound of the type-bars is also aided by the elasticity of the fiber, which returns its contacting surface to normal after it has been compressed by a blow.

Used with the vulcanized fiber anvil as its companionate part is the metal spring of practically the same arcuate form. This spring is made from a fiat piece of metal or other material, in which is formed a channel running throughout the length of the spring. An end view discloses this channel to be of a bow-shape running transversely of the spring but not extending to the concentric edges of the latter. Said edges remain flat, and abut the rear surface of said fiber. Any blows on the latter received from the typebars are in large measure absorbed by the fiber. Such vibrations as are not absorbed by the fiber are largely transmitted to the spring. Because of its tension and a dead air-space in'which it functions, the spring in turn largely absorbs such transmitted vibrations. By so doing, the spring gives further aid in eliminating the noise engendered by the blow of a type-bar contactmgwith its anvil. directly furthers a type-bars.

It will also be seen that, in order to maintain in full the inherent advantages ofthe companionate anvil parts above described, they are combined in a special manner with said type-bar segment. The latter is channeled in its front surface along a line parallel with its curved edge. Said channel in cross-section is T-shaped, forming shoulders that overhang and can retain a flange formed on the concentric sides of the fiber. As the fiber is always concurrently inserted with its spring, the channel then retains both members. At the same time the transverse bow in the spring keeps itself and its abutting fiber in close engagement with the channel. This spring quality also take up any slight inaccuracies in the machining of the channel, the spring or the fiber. When the fiber and spring are concomitantly inserted or withdrawn through the end of the channel, the spring in a measure reinforces the fiber and minimizes the possibility of breaking the latter. I

Should the fiber or spring cease to function properly they are easily replaced. This is of great importance as the replacement can be accomplished without undue delay and without a large labor charge. Furthermore the fiber and spring are of inex nsive material, and are cheap to manu acture. Finally, the fiber anvil, by providing duraquicker rebound of the bility, permits the use of material in the neous retainin type-bar segment which is softer, lighter and more easily machined than cast iron.

Besides the self-retaining feature of said unit, another retention means can be employed. Said retentive means does not always need to be added especially, as it is often found already incorporated to function with other extraneous parts. Such extrameans is found in the bases of the springrackets carrying the guide- The spring by its elasticity also in- I rollers which press a work-gage against the platen. Such roller-carrying spring-brackets are disclosed in my Patent No. 1,302,161, dated April 29, 1919. Said brackets are attached by screws to the cast-iron type-bar segment. They are so located on said segment as to have their bases span the ends of the T-shaped channel aforementioned. When these brackets are removed, the anvil and spring as a unit can be readily inserted or withdrawn. When in place these brackets not only prevent any lengthwise movement of the anvil or spring along its channel, but also keep dust and dirt from entering into the spaces between the spring and the fiber, or between the spring and the channel. Should dirt so collect, it would adversely affect the elastic properties of the fiber and the spring.

Other advantages of having the anvil channel tightly closed by a spring-brackets or other means are also apparent. Should the channel ends be open, or partly so it would reduce the air-cushioning feature in the channel, and the sound-deadening function might be greatly impaired.

In addition, the anvil-and-spring unit might be moved along itschannel by carelessness or through mischief, and one end would then protrude above the type-bar segment. Should such protrusion become sufficient the fiber anvil might be broken off and have to be replaced. This means operative delay and expense. Also, a too-great projection of one end of the anvil would bring its other end beyond the point of engagement with an end type-bar. Said type-bar if actuated without having such anvil would then carry its type to improper contact with a work-sheet on the platen, and cause blurring or penetration.

It is understood, of course, that while the anvil is referred to in the specificationas being made of vulcanized fiber, yet other like materials may be used that will be also suitable for this purpose. The material used should be stifi', wear-resisting, elastic, hard enough to retain its shape after impact from the type-bars, and one that will maintain its working surface intact under the blows received from the type-bars in operation.

Variations may beresorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination with a series of type-bars, of a typebar segment having a groove with undercut sections and a resilient anvil for said typebars inserted in said groove, projections on said anvil, and means to press said projections outwardly against the top surface of said undercut sections, said means including a flat spring between said segment andanvil and having its center bowed to form a sounddeadening air-pocket.

3. In a typewriting machine, the combination with a series of type-bars, of a typebar segment having a groove with overhanging retaining edges and an anvil for said type-bars, said anvil being provided with flanges to co-operate with said overhanging edges when inserted in said groove, and a separate member between said segment and I said anvil to hold the latter in place.

4. In a typewriting machine, the combination with a series of type-bars, of a segment supporting said type-bars, said segment having an arcuate groove, plates to close the ends of said groove and a resiliennt element slidably insertible in said groove and having a strik ng face for said type-bars extending through said groove, and a spring-member in rear of said element to resiliently press and hold'said face to the front of said groove, said ,ooved segment and plates forming a soun deadening enclosed air pocket in rear of said element.

5. In a typewriting machine, the combination with a series of type-bars, of a segment having an arcuate groove with overhanging edges and a resilient type-bar anvil, vulcanized fiber inserted in said groove, projections on said anvil, a spring in rear of said anvil to force said projections against said overhanging edges to hold said anvil inplace, and means fixed to said se ent to prevent accidental displacement o said anvil and spring.

6. In a typewriting machine, the combination with type-bars, of a segment to support the same having an arcuate groove thereln, a fibre anvil inserted-in said groove, and a separate metallic cushion engaging the anvil throughout its length and effective to yieldingly hold the anvil in position in the groove.

7. A type-bar arrester for typewriting machines, including' a bow-sha ed anvil made of hard elastic material'and a ow-shaped backing of springy material engaging the same throughout its length, and means including a type-bar segment to support the arrester throughout its length in the machine.

8. The combination with a system of typebars, a segment for pivotally supporting the same, and means for operating the bars, of a type-bar anvil made of elastic material, and mounted in a groove in said segment, a spring between said segment and the anvil to hold the anvil in efiective position and assist the anvil to cushion the blows of the type-bars, and a stop included in said. segment to limit the movement of said anvil by the spring.

9. In a typewriting machine, the combination with a series of type-bars, of a type-bar segment having an undercut groove and a type-bar anvil in said groove eflfective to normally engage the undercut portions of the groove, and a member to resiliently press the anvil into its normal position.

WILLIAM F. HELMOND. 

